George harry lofts



G. H. LOFTS.

ELECTRICALLY HEATED ARTICLE TO AVOID DAMAGE THROUGH OVEHHEATING.

APPLICATION FILED APR. 15. W20

1,382,101. PatentedJune 21, 1921.

UNITED STATES PATENT, OFFICE.

enonon HARRY LOFTS, or HOBART, resmsnm, AUiSTRALIA.

V ELECTRICALLY-HEATED ARTICLE TO AVOID DAMAGE T To all ug/wmit may concern.

Be it known that I, GEORGE HARRY Lor'rs, a subject of the King of Great Britain, residing atElizabeth street, Hobart, State of Tasmania, Australia, have invented certain new and usefullmprovements Relating to Electrically-Heated Articles to Avoid Damage Through Overheating, of which the following .is .a specification.

.Thisinvention,provide s means whereby articles heated electrically either by direct or alternating current .such as electric irons and like goods ,may be prevented from causiug damage through overheating due to the current, haying.been inadvertently left on,

Anobject :of the inventionis to provide a novel. escapement -.dev i ce. that is held by a pin,madc of a soft metiil suchnas zinc and which, under, the influence of. pressure, ,is sheared, or; parted th us releasin the parts and breakingthe electrical circuit when the n e mea o -m i Heat insulation means are provided .be-. tween theiheating element and the working parts andelectric connections are madein the usual way on the iron, the shape, weight and design ofwhich. is retained .as closely as possible while adapting the same to the operation of my invention: j

It is important in this class of apparatus to so arrange the parts under the influence of the current that it will be difficult, if not impossible, in the ordinary handling of the appliance to receive electric shocks. In my invention the parts are specially desi ned to avoid occurrences of this kind as wi 1 be seen from a closer inspection of the invention hereinafter to be described.

But in order to fully understand the same and the manner in which the invention operates when applied to say, electric irons, re icrence is made to the accompanying draw ing, in which,

Figure l is a side elevation, partly in section, of an electric iron fitted with the cscapcment or cut-off.

Fig. 2 is a detail sectional elevation of the cut-off means that is retained under a nickel plated dome that accords in appearance with the container of the iron.

Fig. 3 shows in perspective view the upper member or shearing washer of the cut off and also the bearing spring.

Fig. 4 is a detail perspective view of the end of the said spring, and

Specification of Letters Patent.

Application filedlpril 15, 1920.

ROUGH ovnnnna'rrlve.

Patented June 21, 1921. Serial Iva-374,146.

Fig. 5 illustrates in plan viewthe lower member of the cut-off.

The invention can be'appli'ed to'the ordinary electric iron and is easily adapted for use :therewith. The main outward alteration will consist of the dome 6 that fits over the annular outwardly turned flange 7 from the container orcover 8.; ;The cut-offis housed within this, part=above the heat insulation!) that liesup'on the iron insole l0 beneath which isthe heating element 11 in contact with the .sole; 12 and is connected electrically in series with-the heating element. 7 r .7 l l A vertical spindle16 preferably of copper, is screwed into theqsole I12 and projects upward intothe dome. The spindle asses through the heating-elementand the insole from each of which it should be heat insulated by13. eposing upon the insulation and about the spindle isa, fixed-iwasher 14 that is made of asbestos wood or otherlikb insulating and heat resisting material. This washer is fitted with carbon contacts 15 or indieuof carbon may have metal contacts. Higher up the spindle is the shearing 0r sliding washer 17 also of asbestos-wood or other hard non-conducting and heat resistmaterial and under. this washer is. a metal plate 18 having depending lugs 19 that are normally in contact with thecarbons 15. Immediately above the washer 17 is an openin 20 through the spindle through which the zinc or other suitable soft metal pin 21 is passed, the face of the washer 17 being preferably grooved diametrically to accommodate the pin.

Bearing below the washer is a stout spring 22 that is mounted in heat insulation 23, and having its end bifurcated and slightly upturned to embrace the spindle and at the same time to bear upon the washer. This spring should be stout and is preferably com posed of leaves of suflicient strength to cause, by its upward pressure on the washer 17, that member to shear off the pin when the heat imparted to the pin through the spindle from its connection with the iron sole is sufficient to soften the same.

The spindle is heavily coated with nickel and the pin 21 is composed of a fusible metal though it should be distinctly understood that it is not intended to be fused but only softened, the spring pressure being enough to cause it to be parted when in that condition. To use a fusibleeleinent in this Connection would be inconvenient and it is dispensed with to avoid the fused metal :idhering t0 the parts comprising the cilt-ofl.

In the an Qf th imitate her or tub 2 l that is closed by a clip and is used to cqnteins eretnins 20. i ,4.

In operation, t 1e ifon'is used in the ordinary way, the heating'eletnent keeping the sole hot. From this the heat flours through the spin'dle' to the'pin While the iron is in use its sole temperaiturewill"remain safe but should it b'ei left on'=a dryfs'urface the tein ieiiatu're of botli sole [end spindle "ii ill u-radirally' rise until the safe point-is eaich'e'cll t this critical temperetu're the pin 20 will lie softened a gid-"ifendered erisily s fe'arable. Then this o'ecurs the'springwill l' 'ft th wsheronthe: spindle and the hr 19 nto I cont'ect with the carbons 15 thus breaking eledtri'cal cont act in the l iron; the temperature oi whichf wdl'lld"othrwisle haife"c6fltinned to increase' until ignition ef' contact ing material occurred. e As be fOreezqi lttitled", the; shearing "Washer 17 is madgef mat/[iii "i s'uehf; as asbestosivood which is li'arid :ml s t' i dqto diigtor of heat. On this f-compamtivelyi cool surface the piii 'lztys vthile being hgitetlat its iffiiddle part'by contest vy'ithfthe.spinclle end this win-be 'fouird w facilitate the sheeting of 11 i t the washer i flacleen and e e tive 0 I 1 '51" i "l 'i:'-' liaving now described my inventionviihat I cleif n' as new and desire to secure byfLet'i tare-Emerita? 3' "=1L Irfakfdi 'tofi' for an electrically heated iii-tide; the m pinatioh qr ad eeted menig be. w ee efl e e nd i -Mee in a ho ei meme.-

member SlHlillilt on the spindle. 1i fusible (pin in thespindlc and forming :1 stop for said shearing mcmbcr. and against which the shez ring member bears, electric contact elements one of which is movable with the shearing member and a spring exerting its tension on said inorzihle contact element and said shearing member to cause the latter to cut the pin and tllQl(3l) enable the movable rontact element to separate from the other Ollt-flct tilfncnt when the fusible pin is renglcrefl'soft'by excessive heat of the heated mmiii'ieiand the conducting spindle igi l n hiifelectricully heated article a heated member, aninsulator thereoin nu insole, separated from the heated member by said in'suhitbrg'a heat conducting spindle projecting from the heated member and through s'ziitl insole"zi'iid saichinsulator, a non-heat conducting sili ezirin i member slidable on the siiindle'fe fusible' 'pin in the spindle and forming e stop for said shearing member, a fixed electrical contact element on the in ei ,?=a-m6v=u51e electrical contact element 'slitla ble"o n"tlie spindle with the shez ring' mffibr alldlifliiii g a lug normally in conteiet Withfini' "i'ixe'd contact element, and 11 Spring exerting its tension upon said movabl' boiitnot'eleine nt and said shearing ncinbet to cause t'lielsitter to cut the pin and thereby enable the movable contact element to'is epai'iitef rom the fixed Contact element when the fusible pin is rendered soft by ex essi're' heettofthe heated member and the coiidiictiri'g spindle.

In testimony whereof I affix my signature.

HARRY LOFTS.

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